Thick-to-thin and thin-to-thick virtual disk provisioning conversion is one of the most common operations performed by the IT staff administering a virtual environment. The allocated spaces of a thin provisioned virtual disk is equal to the used space plus a bunch of bytes while with a thick provisioned virtual disk the maximum capacity will be allocated despite the usage of the drive.
Thin provisioned disks allow IT admins to store more virtual machines in the same datastore. It’s possible to convert a thick provisioned disk to a thin one in a bunch of clicks thanks to the powerful vSphere Web Client, for VMware ESXi virtual machines. It’s also possible to perform the inverse operation.